Vader isn't that young because he isn't Vader - technically. Best as I've been able to sort through he's from the end of the Clone Wars. He and Padme were married when the got here, I believe they're separated now. A few months back we all ended up aged, or de-aged or gender swapped - I was running around like a 10 year old boy for part of that time, but the time I wasn't, Anakin aged up. He remembers the things you remember Vader doing, but he technically hasn't lived any of it yet. This place is strange. His old Padawan, Ahsoka Tano, is here, and he's staying with her at the X-Mansion, along with some others with various super powers that are not from our world.
So far as I know, even when he was aged up, he's not done anything Sith Lord worthy since arriving here. Rey and I have tried to keep tabs.
Ren's from the same point as the rest of us, more or less I think. He was living with the other Leia for a while, then moved in with his boyfriend, Eliot Waugh - a magician, and generally decent seeming sort can't speak for his taste in m - Ren's back at the apartment, but since Leia's been out with us at the Ranch since Han left, he's staying with Padme.
Ren works at a coffee shop, and again, so far as I know he's not done anything Sith Lord worthy since arriving here either.
Like I said, I've more detailed notes I can bring by.